Pathways of carbohydrate metabolism operative in oral bacteria and mechanisms by which cellular metabolism is regulated continue to be under investigation. Current emphasis is placed on 1) the characterization of streptococcal glucosyltransferase (GT) and 2) delineation of the mechanism underlying the inactivation of a cell-associated FT. The extracellular GT produced by S. salivarius has been resolved into two catalytic components by DEAE cellulose chromatography. GRT-I produced a water-insoluble glucan from sucrose while GT-I catalyzed the synthesis of a water-soluble polymer. A mutant was isolated which had an impaired ability to produce water insoluble glucan. This mutant was found to lack the GT-I component, although it did possess GT-S. The data indicate that GT-I and GT-S are products of different structural genes. S. salivarius possesses cell-associated fructosyltransferase (FT) that undergoes rapid inactivation under certain specified conditions. The inactivation process was time dependent and required Cu++ specifically. FT inactivation was blocked by incubating cells at 40 degrees for 60 minutes prior to their introduction into inactivation buffer. Our studies have shown the FT inactivation is mediated by one or more enzymes and preliminary data suggest that one of these is a protease.